Design and coupled analysis of a novel floating offshore wind turbine combined with a fish cage for deep water

Abstract

As floating offshore wind projects expand into deeper waters, floating platforms have emerged as the most viable solution for wind turbine support. The integration of aquaculture within offshore wind farms has gained considerable research interest as an efficient marine spatial utilization strategy. To advance the synergistic development of offshore wind energy and marine ranching, this study introduces an innovative floating offshore wind turbine integrated with a fish cage structure. A 1:6-scaled demo system was developed, incorporating design optimizations derived from full-scale configurations. Frequency-domain hydrodynamic analysis and survivability assessment were conducted to evaluate the demo system's performance under various environmental conditions, including wind-wave-current interactions and tidal variations. A coupled time-domain model was established by quantifying equivalent wind turbine loads and accounting for foundation-mooring dynamic interactions. Results demonstrate that wave and current forces dominate the demo system's response under operational conditions. Platform motion amplitudes and mooring tensions escalate with decreasing tidal elevations. Importantly, safety factors remain compliant with regulatory thresholds even at minimal tidal levels across diverse wind-wave-current directional combinations, confirming Demo II's structural integrity under extreme marine environments.